There are several applications for conventional neutron imager/spectrometers. However, most applications revolve around detecting, locating, monitoring, and identifying nuclear material. Neutrons are, by their nature, resistant to detection, and defy easy imaging and spectroscopy. Detection techniques have mostly been in the form of registering moderated or thermalized neutrons from a fast neutron source. Because these techniques measure the charged particles produced by a neutron interaction, deducing the properties of the parent neutron is ambiguous, besides being difficult.
In one application, registering moderated neutrons comes without any information about the incident direction or energy. Measuring fast neutrons in a bulk detector provides an energy measurement, but lacks directional information. A double-scatter telescope pays the penalties of greatly increased complexity and low efficiency by requiring two neutron scatters, but benefits because the elastic scatter kinematics can be used to constrain the incident velocity vector while simultaneously performing a quality energy measurement.